Rebel fighters retreat from the frontline with Syrian army troops in the town of Maarat al-Numan, on November 17, 2012.(AFP Photo / John Cantlie) / AFP

As international recognition grows for the Syrian National Coalition as the ‘legitimate representative’ of the Syrian people, Islamist groups in Syria have rejected the coalition, unilaterally declaring the city of Aleppo an Islamic state.

Members from 13 Islamist rebel groups, some wearing military uniform, have released a video message rejecting the coalition as a Western tool. Sitting in front of the Quran and proclaiming, “Allah Akbar” the group includes a prominent militant al-Qaeda affiliate the Jabhat al-Nusra. This cell has made headlines for suicide bombing campaigns and as a leader of the fighting in Aleppo.

A key part of the message released online read: "We reached a consensus on the establishment of a just Islamic state and the rejection of any foreign plan from coalitions or councils imposed on those of us inside [Syria] no matter which side it [intervention] comes from," as quoted by the Wall Street Journal.

The release of the message coincides with growing international recognition of the US-European backed Syrian National Coalition which was formed as an umbrella organization to unite and represent all the rebel fractions fighting on the ground.

But despite the new coalition gaining international recognition, there are doubts about it’s legitimacy on the ground. “We do not know who this coalition is, they don’t control anything on the ground and yet the West wants them to be the sole representative of us,” Dr Ali Mohamad, Editor in Chief of the Syria Tribune told RT.

The apparent split in the Syrian rebel camp, between the moderate fractions and Islamist cells, has raised doubts that unified action among the rebels is possible, “I do not think that they will be able to control the rebels on the ground and therefore we cannot talk about the rebels marching under one flag,” Mohamad says.

Washington, meanwhile, says it is inevitable that extremist elements would attack the moderate coalition aimed to bring democracy to Syria.

“It's not surprising to us that those who want an extremist state, or a heavily Islamist state in Syria have taken issue with this,” State Department spokeswoman Victoria Nuland said.

The lack of unity among the rebels appears to be causing the US pause for thought, with Washington yet to fully recognize the coalition.

President Obama has said the US needed more time to know if the coalition “is committed to a democratic Syria, an inclusive Syria, a moderate Syria.” The US leader also added that US will not yet arm the opposition because of concerns extremists might get hold of the weapons.

Some experts believe those fears are likely to be realised.

“The radicals are the ones receiving weapons, money and methods of communication and other logistic support,” Dr Mohamad says, adding that some groups are playing both sides of the game. “The Muslim brotherhood is an important member of the coalition and at the same time the Muslim brotherhood is the main backer and supporter of the unity brigade that fights in Aleppo, which is the same brigade that rejected the coalition.”

Meanwhile, the leader of the Syrian National Coalition, Mouaz Khatib announced from his headquarters in Cairo that he would still negotiate with the Islamists. “We will keep in contact with them for greater cooperation in the interests of the Syrian people.”